Septic tanks constitute a reliable device for the primary treatment of sewage. The treatment systems are passive, extremely stable, simple and inexpensive. They are used, above all, for treating domestic sewage from small communities. The configuration of the tank forces the sewage to pass through the liquid mass contained in it. The slowing down of the flow allows sedimentable solids and substances of specific weight less than that of the water to separate. Furthermore, an anaerobic fermentation process is triggered with the resulting solubilisation and synthesis of part of the suspended solids. In this way, the effluent leaving the tank is conditioned, i.e. it has a limited concentration of solids, transformed for the most part into dissolved and colloidal solids.

TYPES: Single chamber, Two-chamber and Three-chamber.

USE: primary treatment of sewage from toilets.

REFERENCE REGULATIONS: Inter-Ministerial Committee for the Protection of Waters Resolution No.48/77, Legislative Decree No.152/06.

PRODUCT CERTIFICATION: UNI EN 12566-1 small waste water treatment systems of up to 50 PT. Part 1: Prefabricated septic tanks.